Diet and nutrition

Because psychiatric illness affects the whole person, it is not surprising that patients with mental illnesses frequently have nutritional disturbances. Often their diets are deficient in the proper nutrients, or they may eat too much or too little. Obesity and diabetes coexist at a greater than average rate in persons with psychiatric disorders. Nutritional states may also cause psychiatric disturbances. Anemia, a common deficiency disease, is often accompanied by depression.

There is a good deal of study of the influence of diet and nutrition on health (Simpson et al., 2011). It is important that clinicians assess for patients’ use of nutrients such as vitamins, protein supplements, herbal preparations, enzymes, and hormones that are considered dietary supplements. These dietary supplements are sold without the premarketing safety evaluations required of new food ingredients. Dietary supplements can be labeled with certain health claims if they meet published requirements of the U.S. Food and Drug Administration (FDA). They also may be labeled with a disclaimer saying that the supplement has not been evaluated by the FDA and is not intended to diagnose, treat, cure, or prevent any disease. Clinicians and consumers both should know, however, that the FDA does not regulate supplements and that claims offered on supplement labels may or may not be accurate.

Some nutritional supplements interact with medications. There are well-known interactions between prescription drugs and vitamins (e.g., vitamin E and anticoagulants), but drug interactions with other supplements are not so easily recognized or well understood. Nurses should specifically ask about patients’ use of supplements during the assessment and should not expect patients to share this information without being asked. Nurses can review the use of the supplements and the potential interactions with foods, drugs, and other supplements to reduce risks. As an example, a serious hypertensive reaction can occur when a patient who is taking a monoamine oxidase inhibitor (MAOI) for depression ingests a food that contains tyramine, such as aged cheese, pickled or smoked fish, or red wine.

Megavitamin therapy, also called orthomolecular therapy, is a nutritional therapy that involves taking large amounts of vitamins, minerals, and amino acids. The theory is that the inability to absorb nutrients from a proper diet alone may lead to the development of illnesses. The earliest use of megavitamin therapy was for the treatment of schizophrenia, for which niacin was recommended.

Avoiding artificial food coloring became popular in the 1970s for treating children with attention deficit hyperactivity disorder (ADHD) and other developmental disorders. The Food and Drug Administration long ago determined that there is no definitive link between these disorders and food dyes; however, some clinicians and parents believe that children with attention deficit hyperactivity disorder are vulnerable to synthetic color additives (Food and Drug Administration, 2011).

Nutritional therapies are used to treat a variety of disorders, including depression, anxiety, ADHD, menopausal symptoms, dementia, and addictions. For instance, lower rates of anxiety and depression are reported among vegetarians than among non vegetarians. An analysis of the vegetarian diet found a higher antioxidant level compared with the non vegetarian diet, which suggests that antioxidants may play a role in the prevention of depression.

The efficacy of omega-3 fatty acids continues to be studied in the treatment of depression and bipolar depression. In a meta-analysis of studies of omega-3 supplements, Eisenberg and colleagues (2006) concluded that they could recommend them as adjuncts to standard treatment for depression and bipolar disorder. Chiu and colleagues (2008) reviewed epidemiological evidence, preclinical trials, and case-controlled studies on the use of omega-3 fatty acids and recommend that patients with depression and bipolar depression follow the same guidelines as for the American Heart Association. These stipulate that adults eat fish at least twice a week. Some authors (Chiu et al., 2008) argue that patients with mood disorders, impulse-control disorders, and psychotic disorders should consume 1 gram of omega-3 fatty acids a day.

Certain nutritional supplements, including S-adenosyl methionine (SAMe) and the B vitamins (especially vitamin B₆ and folic acid), also appear to improve depression (Lakhan & Vieira, 2008). Currently, B vitamins and folic acid are also being seen more favorably for the management of bipolar illness and schizophrenia. According to Lake (2006), these vitamins often augment conventional care with antipsychotic, antidepressant, and antimanic medications. The researchers recommend that combining such approaches with exercise and meditative practices such as yoga is helpful. In a recent random, controlled trial investigating vitamins B₁₂ and B₆ and folic acid for the onset of depressive symptoms in older men (Ford et al., 2008), the vitamin supplements were found to be no more effective than placebo.